Design philosophy
One of the biggest pitfalls while designing an application for cross-platform use is to impose the design patterns from one OS to the other one. In the mobile world, each platform and users of those platforms have certain expectations from an application. These expectations can be as insignificant as an icon on a common feature access button (for example, the share button on iOS and Android), or as important as the layout of a view (for example, tab buttons on the bottom and top of a view on iOS and Windows Phone, respectively). In this paradigm, the designer's responsibility becomes much more complex, since the design, while creating a brand for the application, would need to be inviting and appealing for the users of the platform.
User expectations
Mobile platform users are creatures of habit. One of the key deciding factors of the adoption rate of a mobile application is how easy it is to use and how discoverable the features are for the platform users. It is important...